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Date: Fri, 11 May 2012 08:39:38 -0500
From: Robin Holt <holt@sgi.com>
To: Peter Zijlstra <a.p.zijlstra@chello.nl>, Ingo Molnar <mingo@kernel.org>
Cc: linux-kernel@vger.kernel.org
Subject: Commit cb83b62 fails to boot with a divide by zero error.
Message-ID: <20120511133938.GG3751@sgi.com>
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Ingo, there is a breakage in the x86/master branch.

While testing some of our configurations, we found they would not boot.
The following got things working:

--- linux.orig/kernel/sched/fair.c      2012-05-11 06:29:44.000000000 -0500
+++ linux/kernel/sched/fair.c   2012-05-11 06:31:52.217156410 -0500
@@ -3835,7 +3835,7 @@ static inline void update_sg_lb_stats(st
        }
 
        /* Adjust by relative CPU power of the group */
-       sgs->avg_load = (sgs->group_load*SCHED_POWER_SCALE) / group->sgp->power;
+       sgs->avg_load = (sgs->group_load*SCHED_POWER_SCALE) / max(group->sgp->power, 1);
 
        /*
         * Consider the group unbalanced when the imbalance is larger


We found that reverting the commit:
cb83b62 (x86/sched/core) sched/numa: Rewrite the CONFIG_NUMA sched domain support

also got things working.

Thanks,
Robin Holt